Some media files are associated with a rule that specifies an action to be taken if a playback event occurs. For example, the media file can contain preview or promotional content of a full-length media file (e.g., a trailer of a movie or a short clip of a music single), and the rule can specify that, at the end of the playback of the promotional content, a connection is to be made to a web site to allow a user to purchase the full-length media file. A problem occurs, however, when such “preview-connect” media files are played by a media player that is not aware of the rule either because the media player is not aware of rules in general or because the media player is aware of some types of rules but not the type of rule being used with a given media file. In such situations, the media player either rejects playing the media file (e.g., because it does not understand the header of the file, which can contain the rule) or plays the media file but ignores the rule (and, therefore, does not perform the action specified in the rule). Both outcomes are undesirable because either the promotional content is not played at all and therefore does not promote the full-length media file, or the promotional content is played but does not trigger a mechanism to allow the user to purchase the full-length media file.